Practice portal › Current Electricity › Cells, EMF and Internal Resistance

Two batteries, one of emf 18 volts and internal resistance 2 Ω and the other of emf 12 volts and internal resistance 1 Ω, are connected as shown. The voltmeter V will record a reading of

Asked in CBSE AIPMT 2005 · Combination of cells

Figure: Combination of cells
Answer: (4) 14 volt

Step-by-step solution

Both batteries sit between the same two rails with the same polarity, so they are in parallel; the voltmeter reads the rail-to-rail p.d.

Circulating current: I=(18-12)/(2+1)=2 A (out of the 18 V battery, into the 12 V one).

Terminal p.d.: V=18-2×2=14 V.

Check: V=12+2×1=14 V.

Why the other options are wrong

More Cells, EMF and Internal Resistance questionsAll Cells, EMF and Internal Resistance questions →

Reading this solution needs no sign-in. You only sign in to practise against the clock and keep your progress.

Practise this with a timer